Along an assembly line, various types of articles, such as for example, diapers and other absorbent articles, may be assembled by adding components to and/or otherwise modifying an advancing, continuous web of material. For example, in some processes, advancing webs of material are combined with other advancing webs of material. In other examples, individual components created from advancing webs of material are combined with advancing webs of material, which in turn, are then combined with other advancing webs of material. In some cases, individual components created from advancing web or webs are combined with other individual components created from other advancing web or webs. Webs of material and component parts used to manufacture diapers may include: backsheets, topsheets, leg cuffs, waist bands, absorbent core components, front and/or back ears, and fastening components. Once the desired component parts are assembled, the advancing web(s) and component parts are subjected to a final knife cut to separate the web(s) into discrete diapers or other absorbent articles.
Some diaper components, such as leg elastics, barrier leg cuff elastics, stretch side panels, and waist elastics, are constructed from elastic laminates. Such elastic laminates may be assembled in various ways depending on the particular diaper design. For example, some elastic laminates may be constructed from one or more nonwoven substrates bonded to an elastic film. In some configurations, the elastic film may be stretched and then bonded with the nonwoven substrates to form an elastic laminate.
Some existing elastic laminate assembly operations may have certain drawbacks. For example, manufacturing operations may be configured with machines adapted to grip and stretch the films before bonding the stretched films to other substrates, such as nonwoven layers. With some gripping operations, portions of the film may remain unstretched in the assembled elastic laminate. Such unstretched portions of the film may add no benefit with respect to the desired elasticity of the assembled elastic laminate. However, the unstretched portions of the film may be bonded with one or more nonwoven layers to help anchor and secure the film to the nonwoven substrates. In addition, the nonwoven layers may be bonded directly to each other in areas where the elastic film is not present. In use, the elastic laminates may be stretched by applying forces to the elastic laminates in the regions where the unstretched portions of the film are anchored to the nonwovens. As such, when assembling elastic laminates, it may be advantageous to utilize bond configurations that help to ensure that the unstretched portions of the film and the nonwovens remain bonded together and do not separate from each other during use. However, such bond configurations used to bond nonwovens to each other and/or to unstretched portions of the films may not be suitable for bonding stretchable portions of films to the nonwovens and may detract from the desired stretch properties, aesthetic appearance, and/or tactile impression of the assembled elastic laminate. Conversely, bond configurations used to bond stretchable portions of films to the nonwovens may not be suitable for bonding nonwovens to each other and/or to unstretched portions of the films, because such bond configurations may not provide the strength needed to ensure that unstretched portions of the film and/or nonwovens remain bonded together during use.
Consequently, it would be beneficial to provide methods and apparatuses for assembling elastic laminates that are configured to apply pluralities of bonds with different bond densities in different regions of the elastics laminates.